This invention relates to bicycle power meters used to indicate the amount of power expended by the bicyclist during cycling. More particularly, this invention relates to a universal mount bicycle power meter module capable of being fitted to any bicycle for enabling the generation of electrical signals from which power can be determined.
Bicycle power meters are being increasingly used by both professional and amateur cyclists as an aid in developmental training. Several different types of bicycle power meters are available, some of which use strain gauges to measure the force applied by the cyclist to the crankset, the bottom bracket or the rear wheel hub. While effective in providing electrical signals representative of applied force, known bicycle power meters using strain gauges are relatively expensive and somewhat difficult to install.
Commonly assigned U.S. Pat. No. 8,370,087 issued Feb. 5, 2013 for “Bicycle Power Meter With Frame Mounted Sensor” discloses a bicycle power meter which is relatively inexpensive and easy to install at the point of manufacture, at the retail level and by the end user. The bicycle power meter has a strain gauge sensor assembly mounted on a relatively compressible web portion of the end of the rear fork of the bicycle frame. The relatively compressible web portion is near the rear hub and subject to the forces exerted by the cyclist to the crankset, and transferred via the chain, and sprocket assembly to the hub. The sensor assembly has two ohmically interconnected stretch sensors each having a first layer bearing a variable resistance element, whose resistance changes with displacement of the compressible web portion, and a second layer for providing support for the first layer. The sensor assembly is connected in a bridge circuit to two other resistances to generate signals representative of cyclist applied force. These signals are processed along with velocity signals to generate power signals and the power signals are supplied to a display. While this bicycle power meter overcomes the disadvantages inherent in previously known bicycle power meters, the application is limited to those bicycles having the relatively compressible web portion of the bicycle frame. Not all bicycle frames have this construction.